Ultimate Guide To Rangefinders

Ultimate Guide To Rangefinders

Rangefinders have been around for decades; the tool is useful for many different activities. 

The main job of rangefinders is to measure the distance between the device and a target in the distance. 

These helpful devices are pretty versatile and can be used for golfing, hunting, forestry, 3-D modeling, and more. 

If you are into any of those activities, you may be thinking of purchasing a rangefinder.

However, there are a lot of products out there, so it can be hard to choose. 

The best way to choose the right product is to become familiar with how these devices work and what kinds of rangefinders are out there. 

This ultimate guide to rangefinders will explain everything you need to know, including the history of rangefinders and how they work.

We will also cover how to use a rangefinder and how to test your device. 

Lastly, we will give you a few helpful tips on maintaining your rangefinder. Let’s get into it. 

What Is a Rangefinder? 

What Is a Rangefinder? 

A rangefinder is a device used to measure the distance between you and the target.

Most rangefinders will provide an accurate reading within one yard of the actual distance. 

Most rangefinders will use a laser beam that determines the distance from the viewer to the target.

However, you can also find rangefinder cameras, optical rangefinders, and ultrasound rangefinders. 

Rangefinders can come in handy for a few different situations. First of all, many hunters use these devices while out hunting.

Military personnel also take advantage of these instruments while on duty. Some other uses for rangefinders include 3-D modeling, forestry, and sports. 

History of Rangefinders

History of Rangefinders

The first rangefinders were called rangefinding telemeters. Telemeters are a type of rangefinder device used to measure the distance between the device and a remote object.

James Watt invented the very first telemeter rangefinder in 1769. People used this particular telemeter in surveying canals around 1770. 

Telemeter rangefinders were also often used in World War II.

These devices consisted of two telescopes focusing on the same target but at different distances on one baseline.

The way that the device found the range was by measuring the bearing difference between the two telescopes.

The final range was calculated by solving a skinny triangle solution. 

It wasn’t until the 20th century when camera rangefinders started to appear. 

Around 1916, the first camera rangefinder appeared; it was called the 3A Kodak Autographic Special.

This product was one of many camera rangefinders released during the early 20th century.

Soon after the wave of camera rangefinders, modern rangefinders started to appear, such as laser and ultrasound rangefinders.

How Does a Rangefinder Work?

How Does a Rangefinder Work?

In this section, we will explain how rangefinders work.

There are four main kinds of rangefinders, including laser, optical, camera, and ultrasonic rangefinders. We will discuss all four. 

Laser Rangefinders 

The most common kind of rangefinder you will find today is laser rangefinders.

These devices use laser beams to calculate the distance between you and the target. 

Let’s take a look at how a laser rangefinder works and what the basic process involves. 

  1. The user will press a button on the rangefinder, which will release a laser beam from the device.
  2. The laser beam will bounce off a distant target.
  3. The device’s high-speed clock will measure the total time it took for the laser beam to travel to the object, bounce off the object, and return to the device.
  4. With the data from this measurement, the rangefinder will calculate the total distance from the target.
  5. The calculated distance will display on the rangefinder screen.

While this is the basic process you will see in many modern laser rangefinders, the system will vary between devices. 

Optical Rangefinders 

Another kind of rangefinder you might come across is optical rangefinders. These devices use a series of mirrors and lenses to do the job. 

Optical measuring devices use lenses and mirrors to create a double image.

The user can then rotate a dial on the device and bring the images on the mirrors together and merge them into one image.

The dial on these devices has a distance indicator. When the user merges the two images, they can read the distance on the dial. 

Ultrasonic Rangefinders

Ultrasonic rangefinders work similarly to laser rangefinders. In these devices, a wideband frequency is emitted from a transducer.

The transducer sends out narrow sound wave beams which bounce off a distant target.

The ultrasonic receiver then picks up the returning signal and determines the distance. 

Types of Rangefinders

Types of Rangefinders

There are a few different kinds of rangefinders. In this section, we will review laser, optical, camera, and ultrasound rangefinders.

By the end of this section, you will know what kind of device will be best for you.

Different devices work better for certain activities, so it is good to know the pros of each model. 

Laser Rangefinders

Laser rangefinders are the most common model you will find. They are easy and quick to use and are versatile. 

  • Golf Rangefinders: Many golf rangefinders use laser technology. Many manufacturers have built golf rangefinders that are designed to find the flag on the course. The main purpose of golf rangefinders is to determine the location of the flagstick so the player can improve their aim. 
  • Hunting Rangefinders: Another popular kind of laser rangefinders is hunting rangefinders. Lots of pro hunters use these devices since it is hard to judge distance accurately when you are surrounded by trees. On top of low visibility, the constant change of sunlight and weather also makes it difficult. 

Hunters will often use a rangefinder for ranging their hunting grounds.

They will choose a landmark and range it, then do some target practice after to determine shooting accuracy. 

Optical Rangefinders

Optical rangefinders are not as popular as laser models are, but they still have a purpose.

Historically, optical rangefinders were used in the military. Soldiers used the devices to determine the range of targets. 

Optical rangefinders also have another main use other than for military purposes.

In the past, these devices were popular in the sports industry, especially for golf.

While optical rangefinders are out of date, they still work well if you can get your hands on one. 

Camera Rangefinders

Camera rangefinders require a bit of expertise to get the hang of. These models are not as simple as laser rangefinders. 

These rangefinders are entirely manual, meaning that the photographer must have a firm grasp on concepts such as ISO, aperture, and shutter speed.

While the camera may have a steep learning curve, these devices can produce one-of-a-kind photos. 

Many photographers prefer camera rangefinders since they are more lightweight and produce sharper images. 

Ultrasonic Rangefinders

When it comes to activities such as hunting and sports, ultrasonic rangefinders are few and far between. 

However, these devices have a few different purposes. For example, many homeowners will use ultrasonic rangefinders for home security.

Furthermore, you can use an ultrasonic model for navigational purposes and object avoidance. 

One of the main benefits of ultrasonic rangefinders is that they use sound to detect distance.

This fact means that these devices work just as well in complete darkness as they do in daylight (this is why they work well for security purposes). 

How To Use a Rangefinder

How To Use a Rangefinder

In this section, we will explain how to use a laser rangefinder.

Laser models have flooded the modern market due to their modern technology, leaving older models such as optical rangefinders in the dust. 

Before you start fiddling with your new laser rangefinder, make sure to review the manual first, and try to watch some videos/read some blogs on your specific model.

Doing this will make the process easier. Finally, keep in mind that it will probably take a while to get the hang of this device. 

So, how do you use a laser rangefinder? 

Almost anyone can use one of these models since they are pretty simple.

There are a few basic steps to follow when using this device for the first time. 

  • Turn the rangefinder on. The power button will typically be on the top of the rangefinder
  • Decide what mode you want to use. Many laser rangefinders will have a few different modes you can use. Before you activate the laser, set the device to what mode you need. You should also adjust the device to account for the slope at this stage, if there is any. 
  • Find your target through the rangefinder. Now that you have everything else set up, it is time to find your target. Bring the device up to your eyes and find your target. After you find your target, activate the laser. 
  • Find out the yardage. After the laser is activated, the correct yardage should appear on the device’s screen. 

In just a few easy steps, you can get an accurate reading with your rangefinder.

However, it is worth noting that you should aim the device at a reflective surface to get the most accurate reading.

The higher amount of area that the beam hits, the more accurate the reading is. 

Another helpful tip is to use your phone or smartwatch to read the results. Many rangefinders will allow you to connect mobile devices to read the results easier. 

How To Aim the Rangefinder

To get the most out of your device, you should know how to aim your rangefinder properly, whether hunting or golfing. 

Before you aim at your target, you can start by aiming your device at the ground. Then, press the button, and let it start measuring the distance.

Once you see a reading on the display screen, you can aim your device at the target and press the button again. 

How To Accommodate for Slope

If you use rangefinders while golfing, you may want to accommodate for slope.

If your rangefinder has the ability, it can calculate the slope between your location and the target. But how do you do that? 

First of all, you will need a device that comes with a slope setting; not all rangefinders have this setting.

Let’s find out how to take advantage of this setting. 

  1. Position yourself in a way that is parallel to the target. 
  2. Adjust the sight and make sure the image is as clear as it can be. 
  3. Aim the range finder at the ground and press the button to activate it.
  4. Aim the range at your target, and press the button again. 
  5. Read the results. 

If your rangefinder has a slope setting, it should calculate the slope as well as the return angle.

Testing Rangefinder Accuracy

Testing Rangefinder Accuracy

Now that you know how to use a rangefinder let’s find out how to test your rangefinder accuracy. 

Compare Your Rangefinder With Other Models

The easiest way to test the accuracy of your rangefinder is to compare the reading of your rangefinder with other models. 

Ideally, you should compare your model with two other devices. However, if you only have access to one other rangefinder, that will work as well. 

To do this, choose one target for all three devices.

Make sure you mark where you are standing on the ground as well; this way, you can be sure you are standing in the same position with all devices.

With the first device in hand, aim at the target and activate the laser.

When you get the first reading, write it down on some paper. Do this with the next two rangefinder devices. 

With this data, you will be able to see if your rangefinder is accurate. While the readings may not be exactly the same, they should be within one yard of each other. 

Go to a Shooting Range

If you do not have access to other rangefinders, don’t worry. There is another simple way to test the accuracy of your device. 

Take your rangefinder and visit your local shooting range. Many shooting ranges will have targets marked with the distance.

If the targets are not marked, the staff can tell you how far the target is from you. 

Once you find a good shooting range, take out your rangefinder and pick a target. Aim at the target and activate the laser.

Once you have the reading, compare the reading on your device to the shooting range target. 

You should do this with a few different targets to be sure of the accuracy of your device. 

What You Should Do if Your Rangefinder Is Not Accurate

Perhaps you tried one of the two techniques above and found that your rangefinder did not produce accurate readings.

If this is the case, there are a few things you can do. 

First of all, you may need to calibrate your rangefinder. You can refer to your manual to find out how to do this. 

If calibrating your device does not work, you may need to have a professional take a look at your rangefinder.

There could be a few things causing this problem that they will be able to discover.

Rangefinder Maintenance

Rangefinder Maintenance

Perhaps you already have a rangefinder, or you are interested in buying one. Whatever the case, it is important to know how to take care of it.

Most devices are pretty small and can easily be damaged. Keep reading to find out how to prevent costly repairs and increase the lifespan of your device. 

General Care Tips

Avoid Direct Sunlight 

As with any kind of technology, direct sunlight is a bad idea.

While the device will be fine in the sun for a few minutes, you should always avoid leaving it in the sun for over half an hour. 

The lens of your rangefinder is sensitive to ultraviolet light. Therefore, if too much direct sunlight shines on the lens, you will need to replace the entire device. 

Furthermore, direct sunlight can also disorient the sensor. If you use the device on a hot day, you might not get accurate readings. 

Doing so will cause the rangefinder to overheat, which could lead to further damage.

If you are using the instrument on a sunny day, try to find a nice spot in the shade or cover it. 

Protect Your Device From Moisture and Extreme Temperatures

While this may be a given, it is worth mentioning. Avoid exposing your device to too much moisture.

While a few raindrops will not be the end of the world, a high amount of water could damage it.

Not only can water mess with the electronic components, but it can also cause the lenses to fog up. 

Furthermore, do not use or store your rangefinder in extreme temperatures, whether it is too hot or too cold. 

Handle Your Rangefinder With Care

Your rangefinder will have many delicate parts that can easily break, such as the lens.

You should always handle it with care, and avoid dropping it on the ground. Furthermore, avoid hitting the rangefinder against hard objects.

All of these events could lead to scratches, dents, and could even break the instrument. 

Whenever you are handling it, always be aware of how delicate the device is. 

Use a Case When Traveling

When you are on the go or traveling, you should always bring a rangefinder case with you.

Even when you hit the golf course for an afternoon, bring along the case. 

Keep your device in a padded case to avoid scratches and damage. Furthermore, even when it is in the case, do not leave it near any edges.

Another thing to keep in mind is to keep the case out of direct sunlight to avoid over-heating. 

Store the Device Safely

When you are not using your rangefinder, make sure to store the device safely. You can store the device in a padded case as well. 

Try to find an area that is climate-controlled to store the rangefinder in, such as a house or heated garage.

Furthermore, make sure that the instrument will not fall from a tall height such as a high shelf; this could break the lens. 

Performing Maintenance 

While it may be tempting to perform your own maintenance on a rangefinder, try to avoid this.

You should always go to a professional when it comes to repairing your device.

As mentioned before, there are a lot of delicate parts on rangefinders. It would be easy to accidentally damage something if you don’t know what you are doing. 

At the very least, refer to the rangefinder manual before performing any kind of maintenance.

If you simply need to adjust a few things, you will probably be fine doing it yourself; just make sure to become familiar with the model. 

Cleaning Your Rangefinder

Lens Cleaning 

The lenses on your rangefinder will inevitably become dirty. You will need to clean off any dust and dirt that accumulates.

If you don’t take the time to clean your lens, you will not get a clear image when looking in the viewfinder.

All you need to do is purchase a lens cloth and some lens cleaning solution. Then, clean the lens in light circular movements, avoiding pressing too hard. 

Removing Stains

You will also need to remove some stains from time to time. If the stain will not come off with a normal lens solution, you may have to use something stronger.

You can wipe stubborn stains with pure alcohol and a soft cloth, preferably velvet.

However, you can avoid stains such as these if you regularly dust your rangefinder. 


Rangefinders are helpful devices that provide an accurate reading of the distance between you and a target. 

There are about four main types of rangefinders: laser, optical, camera, and ultrasonic rangefinders. 

Laser rangefinders are the most popular models nowadays. You can find these devices for activities such as golfing and hunting. 

Ultrasonic rangefinders are mostly utilized for security purposes because they can perform just as well in complete darkness. 

When it comes to laser rangefinders, it is quite easy to use them.

All you have to do is turn on the device, decide what mode you want to use, find your target through the viewfinder, and activate the laser.

The device will then calculate the yardage and appear on the digital screen.

There are a few general care tips you should follow to lengthen the life of your device.

Ensure to keep it out of the sun, avoid moisture and extreme temperatures, handle the rangefinder with care, use a case when traveling, and store the device safely.